[Vol. 6 



138 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



5. Richards' solution (E) 1 which contains 0.5 gin. mono- 

 basic potassium phosphate, 4 gms. potassium nitrate, 2.5 gms. 

 magnesium sulphate, 10 gins, ammonium nitrate, 50 gms. cane 

 sugar, and a trace of ferrous sulphate in 1000 cc. of water. 



6. Sap from Acer sac char inum. 



The following twelve fungi were employed in the experi- 

 ments: Coniophora cerebella Pers., Daedalea confragosa 

 (Bolt.) Fr., D. quercina (L.) Fr., Lentinus lepideus Fr., Len- 

 zites vialis Pk., Merulius lacrymans (Wulf.) Fr., M. pinastri 

 (Fr.) Burt, Pleurotus sapidus Kalchb., Polyporus lucidus 

 (Leys.) Fr., Polystictus hirsutus Fr., P. versicolor (L.) Fr., 

 and Trametes Peckii Kalchb. 



Methods 



Twenty-five-cc. quantities of the above-mentioned solutions 

 and decoctions were pipetted into Erlenmeyer flasks (125 cc. 



capacity)- Duplicates of these were inoculated with each 

 fungus after the flasks were sterilized at 15 pounds pressure 

 for 20 minutes. Control flasks of all solutions were prepared 

 in duplicate. 



Before inoculation the fungi w T ere all grown on agar-poured 

 plates. The nutrient agar was made up in the following man- 

 ner : To 1000 cc. of potato water (from 200 gms. of peeled and 

 sliced potato cooked for 30 minutes in the autoclave at 15 

 pounds pressure) were added 20 gms. of cane sugar, 10 gms. 

 of potassium nitrate, 5 gms. of monobasic potassium phos- 

 phate, and 20 gms. of agar. After growth of the fungi the 



plates were cut into small squares (about 8 mm. square) which 

 were used as inocula. Thus the amount of agar added to the 

 cultures introduced to all a negligible amount of nutrient ma- 



»"& 



terials. Similar squares of agar from uninoculated poured 

 plates were added to all control flasks. All cultural operations 

 were performed in a transfer room which was thoroughly 

 steamed before each operation. There were no contamina- 

 tions in the 332 cultures involved in the data discussed below. 



1 Richards, H. M. Die Bceinflus-amu; flea Wachstluims einiger Pilze durch 

 chemische Rdze. Jahrb. f. wiss. Bot. 30: 605-688. 1897. 



